Authors: Xiaoxiang Sun Jianxi Zhao Tixian Chen Xiaowei Liu
Publish Date: 2015/11/25
Volume: 20, Issue: 3, Pages: 657-664
Abstract
Commercialgrade fumed silica was dispersed by mechanical shearing and/or ultrasonic force to produce dispersed silica particles with different sizes The lightscattering technique and a diagrammatic method of extrapolation used to eliminate the influence of particle interaction were applied to determine the size of the particles Then the effect of particle size on the gelation of fumed silica in sulphuric acid medium as well as some electrochemical properties such as ion transfer and redox capacities of lead in the gelled electrolyte were examined The results showed that the size of dispersed particles affected the gelation of fumed silica itself with increasing size the thixotropy of the system increased and the gelling time decreased particularly for those particles obtained only by simple stirring The strength of the gel increased with increasing particle size At an identical silica content the increase in particle size led to a decrease in the density of the particles this weakened the threedimensional structure of the silica particle network and reduced the efficiency of ion transfer However the effect of silica particle size on the redox capacities of lead was negligible
Keywords: